2-amino-5-benzyl-1, 3, 4-thiadiazole and acid salts thereof



UNITED STATES PATENT OFFICE 2-AMINO-5-BENZYL- 1,3,4-'IHIADTAZOLE AND ACID SALTS THEREOF Lucas P. Kyrides, Ferdinand B. Zienty, and

George W. Steahly, St. Louis, Mo., assignors to Monsanto Chemical Company, St. Louis, Mo.,

a corporation of Delaware No Drawing. Application March 12, 1945, Serial No. 582,412

2 Claims.

This invention relates to therapeutic agents possessing analgesic action and more particularly to a novel analgesic agent and to a process for its preparation.

The present invention is based on discovery 5 The novel compound of the that the novel compound, 2-amino-5-benzyl-L3A- 2-amino-5- benzyl-1,3,4-thiadiazole, is also useful thiadiazole and its acid salts, such as the hydroas an intermediate in th preparation of other chloride, possess marked analgesic action. This therapeutic agents. For example, the compound compound has the structure may be condensed with N-acetylsulfanilyl chloride and the sulfanilamide derivative thus ob- OH 35 IL tained may be hydrolyzed to remove the acetyl residue, forming thereby 2:sulfanilamido-5-- S benzyl-1,3,4-thiadiazole, a bacteriostatic agent. The analgesic agent of the present invention While e Compositions f e present invenmay be prepared by anydesired method A novel tion have been described and illustrated in the process for preparing the compound is illustrated foregoing specification and examples, it s o be in t following example; observed that the present invention is not to be construed as being limited in respect to any par- EXAMPLE ticular substances, proportions, conditions or 2-amino-5-benzykLSA-thiadiazole combinations except as defined in the claims. We claim: A mlxture of grams (0.27 mole) of th1osem1- carbazide and 42.5 grams (0.275 mole) of phenyl- 2 ammo 5 benzyl'lgf4'thladlazole. Eg acetyl chloride was prepared and agitated for fol. s as an fi 3? i f m 2 2 hours at a temperature below 100 C. After 25 2;??? m e prepam Ion of 0 er 8343911 10 several hoursvof additional agitation, the mixture became solid At this point the condensegion was m2;1 gfigdlsalt derivatives of the compound defined substantially complete. The solid was issolved v in approximately 300 cc. of warm 50% alcohol. The resulting solution was cooled and rendered GEORGE W S'TEAHLY alkaline with 20% caustic soda solution. The mixture was filtered and the solid material was washed with 250 cc. of water and dried at 90 C. 1 REFERENCES CITED Weight, 25.9 grams (49.5%). Melting point, The following references are of record in the 191-195 0. When recrystallized from ethyl a1c0 file Ofthis patenfi hol the melting point was 2:12-20? C. 5 b 1 3 5 UNITED STATES PATENTS Acid salt derivatives of e 2-aminoenzy I 1,3,4-thiadiazoles, such as the hydrochloride, gg g'fg ggi g: a1 Pf fi sulfate, benzoate and acetate may also be employed as thereapeutic agents. The acid salt derivatives may be prepared by reacting in equimolecular proportions 2-amino-5benzy1-1,3,4-thia diazole with the appropriate acid in aqueous or organic solvent solution, according to the procedure known in the art for the preparation of the acid salt derivatives of basic organic nitrogen compounds. 7

present invention,

OTHER REFERENCES Chemical Abstract-W01 3e v0o94 1942. Beilstein, 4th Edition-vol. 27-pp. 629 and 647. 

1. 2 - AMINO - 5 - BENZYL-1,3,4-THIADIAZOLE, PREPARED FOR USE AS AN ANALGESIC AND AS AN INTERMEDIATE IN THE PREPARATION OF OTHER THERAPEUTIC AGENTS. 